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The OPC Community Forum.
DeltaV vs. Processlogix
By ING MOLINA on 4 August, 2005 - 11:35 am

i work as an instrumentation an control engineer in an metalurgical complex in mexico, an Electrolitical zinc plant. and right now we are using diferent control systems, some of them are PLC-5, Contrologix, several SLC, all of them from allen bradley. we also have flex i/o via ethernet, and devicenet systems. but now here they want to change all that to a deltav system using FFieldbus instruments. i'm not really sure about that, i think is more expensive, less friendly, the OPC with the plc don't work very well, and the FF instuments are more complicated than regular 4-20 instruments. these PLC have worked very well. i am not telling that the deltav sucks, i know is a very good DCS but i would really like to know the bad things about this system (deltav) and if it's better the processlogix than this one. thanks.

By Jorge Monsalvo on 5 August, 2005 - 12:20 am

I'm not an expert on Delta V, bu t I think is not a matter of "good" or "bad". Personally I don't like the instrumets buses in application where security or working time must be consider. Think that all your process is pending from one(or two) cables. A problem there and say goodbay to your plant. I worked on one or two plants with DV as operation DCS (ESD works on a diferent system) and found some problems: OPC drivers, Slow response from operation stations (due by the animations) and comunication modules
settings. Other problem that people in plant found was you can not make changes on engineering without make a complete download or the module involved. Sometimes this means that you must stop part of your plant for small modifications. I repeat that I am not an expert, so things I said could be modified in new versions. Otherwise if you have many process with different control procesors you must think in integration. Move to a DCS could be a solution but if you must deal with OPC or Ethernet/IP in the new DCS, a good idea could be create an industrial network, use a HMI software and some applications, upgrade old controllers and operate your actual controllers "like" a DCS.

IVControl S.R.L.

Hola Ing. Molina,

My name is Luis Carrillo from Rockwell Mexico, We could contact you if you like it and comment the main differences between Delta V and the Process Solution from Rockwell. My mail is

The Process Logix right now is no longer available for new applications.

By Hugo at IAI on 5 August, 2005 - 11:43 pm

Hello Luis,

This is a more or less public forum, and a request for information or comment deserves a public answer. No one expects (well maybe some of the zealots do) you to be perfect. But if you care to comment, then do so publicly. Just speak to the subject at hand from your experience, and try not to slander. That is why I subscribe to this forum - for a daily injection of levity and learning. By offering to communicate privatly you do this forum a disservice (and you do your own reputation a disservice - I am likely not the only one wondering why you will not comment here in the open).


By wboyes@ix, on 6 August, 2005 - 2:37 pm

Actually, since his message was the closest thing to a solicitation this forum permits, his message was proper. He is a Rockwell representative, asking the customer to permit him to make a pitch. Doing more than that is generally frowned upon on this forum.

Walt Boyes
Editor in Chief
CONTROL magazine
Read my blog, SOUND OFF! at

By ING. MOLINA on 23 August, 2005 - 12:39 pm

Thank you all for your opinions, this would really help me about this situation. any more info would be great.

I work for an Emerson rep in Canada and I have implimented many DetlaV systems. DeltaV works well with FF and HART as well as many other communications, however what a site uses is dependent on what is existing. FF is not for every one. FF have advantages and disadvantages (I have never had a customer experienence a problem with removing a device from a segment if done properly). The biggest problem we find with FF is that people are not familiar with it. Understanding 4-20 mA is easy. FF is not as simple. Alot of training is nessesary to get up to speed. For more information go to

If you change to a Delta V system, you will have to purchase all new field instruments. You are going to do a total plant upgrade, it will cost. when you purchase the new field instruments, it is necessary to know the CFF/DD rev for the device.

Good luck.

By Arnold Dillon on 5 August, 2005 - 9:05 pm

If you purchase Delta V you absolutely will NOT have to purchase all new field instruments. Delta V handles traditional 4-20 mA signals, along with Foundation Fieldbus, Profibus, DeviceNet, Asi Bus, and maybe some

-Arnold Dillon

By Jonas Berge on 8 August, 2005 - 7:28 pm

Well, they probably only need to change the instruments if they were to change from 4-20 mA to Foundation fieldbus - which may be a pretty good idea - but is an entirely different topic all together. Regardless of system ultimately chosen, due consideration to fieldbus should be given.

Let me share with you my experience from our (SMAR) system using FF: SYSTEM302.

Knowing and managing standard CFF/DD is not difficult. If you connect a device online you can immediately see the CFF/DD it requires. All CFF/DD come preinstalled on a new system. Files for new versions in the future are available on both the Fieldbus Foundation site and the manufacturer's sites. Other systems may not have all the same capabilities, but I have worked with our instruments on a few other systems as well and they have similar features.

It may often be possible to upgrade existing HART devices to Foundation Fieldbus. If you have purchased a SMAR HART device the past 10-12 years you can upgrade it to Fieldbus by replacing the circuit board. Sensors, transducers, valve bodies, and housing etc. remain the same. Many instrument suppliers promised this in the early nineties, not sure if all delivers on it.

Although replacing instruments to put in fieldbus has a high initial cost, there are long term savings - such as predictive maintenance - you can achieve by making a move to fieldbus technology.

For information on how to migrate to fieldbus take a look at chapter 5 of the yellow book "Fieldbuses for Process Control: Engineering, Operation, and Maintenance" buy online. Benefits of migrating are in chapter 2:

Jonas Berge
Learn fieldbus and Ethernet at your own pace:
Learn OPC and automation software at your own pace:

DeltaV is a DCS system. You can replace any DCS or PLC system without changing your field instuments. The confusion comes from the fact that DeltaV like other systems, can communicate with Foundation Filedbus instruments that requires then FF instruments in the field. But as Other DCS, DeltaV supports in standard existing 4-20 ma Instruments with or without Hart capability or other 0-10v, Serial, ASI...


I'd say neither AB nor DeltaV, but Unity Quantum. Yes, it's Schneider provides you with all the high availability, openess, simplicity, best class redundancy... not only OPC compliance but also XML and VB.

Talking about fieldbus, definitely compatible with not Modbus & Modbus Plus, but also Profibus.

I have had 4 years maintenace experience with DeltaV. It was, from a DCS hardware perpective, pretty reliable.
We also used Fieldbus for all non SIS instrumentation. What you have to remember is Fisher-Rosemount are one of the main "drivers" in fieldbus implementation, and it's in their commercial interest to push it.

Most of our problems came from the fieldbus side.
Now guess whose fieldbus field equipment we used? yup, Fisher-Rosemount. Don't get me wrong, I can't complain about their non fieldbus stuff!

Depending on how many instruments per "drop" you use, you can (and we did, frequently) lose the lot. Are you able to put up with that? I believe that there are redundancy "options" now.

Fieldbus is great whilst there is "communication". You can't take the transmitter out and put it on the bench.You end up replacing modules or whole Instruments to get them working again. Fieldbus Instruments are more expensive.
Most DCS vendors have a library of "blocks", but with Rosemount you have to purchase "licences" for extras that come free with other vendors. My personal recommend would be, yes, use Delta v by all means; but use 4-20mA and Hart.

If the processes are ion exchange to solvent exchange to electrowinning, this is not an ideal foundation fieldbus application. While in particular the ion exchange process lends itself to phase logic for control, most of the I/O is discrete and FFB is an analog substitute.

We are a system integrator and use fieldbus technologies routinely. We also use both DCS and PLC platforms. Granting the process assumptions and unfettered by your expressed preferences, I would recommend a PLC for sequential control and either ASI or Profibus for their discrete capabilities. The PLC5 may not be an ideal platform for the ion exchange process but ControlLogix supports SFC and that would work out nicely.

To justify your preference (ignoring any strengths of the DCS): DeltaV will be much slower than ControlLogix for sequential control. DeltaV does not support ladder diagram as a configuration language so programming your discrete logic will have to be done in FBD (which takes more keystrokes to lay down logic blocks and more time to configure those blocks). DeltaV will have downstream costs (service contracts, upgrades etc) that are not issues in a PLC environment. The configuration environment and the way that is licensed is something you should look into - a guy used to Allen Bradley is going to be a little disgruntled by the comparison.

Hope this helps.

Joe Hohn

By ControlNovice on 16 August, 2005 - 1:11 am

Stick with the AB equipment. You can actually re-use some of the configuration whereas with DeltaV you will have to start from scratch.

We were forced to go with DeltaV at our plant. Pretty much Emerson management took our management (no engineering) to play golf and after that outing we were told that we will be upgrading to DeltaV AND Foundation Fieldbus.

It cost much, much more than if we just upgrading the exising AB equipment and maintenance is a huge problem on the FF equipment.

DeltaV is a good process controller - it just is not justified in your case.

I will suggest go for Deltav upgradation. DeltaV is much more powerful than any AB product. It is user friendly and will save much troubleshooting issues. FF devices are give the exact status of process.

Bottom line is it is one time investment but returns are more.

By deltavexpert on 21 August, 2006 - 12:25 pm

I will always say that go for FF. I have more than 6 years on this System. it works fine and OPC is really Good system and you can easily learn it, very user friendly and convenient rather than others.

FF is really Good one and you can get more and more out of it.

I strongly suggest to go for it. No worries.

visit for more info on DeltaV /OPC/PI systems